I have a 1985 302 V-8 F-150 that has been running rich and to the point where it would not start. Mechanic replaced distributor, ign module, stator, fuel filter, O2 sensor, and added fuel cleaner. When I wne to pick up it started, ran for 15 seconds stalled and they could not get it started. The funny part is that previous to the episode of running rich there were times the engine would purr and then take a spell where it would stall and run rough. Any ideas before I spend more.

Sounds like an intermittant problem which is the hardest to diagnose. I say get another mechanic. Sounds like this one is just shooting in the dark rather than taking volt/ohm readings on things and checking to see if they are to spec. Also it should be able to be hooked up to a diagnostic computer to get an idea of what is going on in there even though it is not OBD II.

EFI 302....probably EECIV.....there is a regulator on the fuel rail that is vaccume controlled.
Seen this valve jam up a few times which makes it run real rich.
First check the vaccume hose going to it for a leak, if ok then pull the regulator.

I have a 1985 302 V-8 F-150 that has been running rich and to the point where it would not start. Mechanic replaced distributor, ign module, stator, fuel filter, O2 sensor, and added fuel cleaner. When I wne to pick up it started, ran for 15 seconds stalled and they could not get it started. The funny part is that previous to the episode of running rich there were times the engine would purr and then take a spell where it would stall and run rough. Any ideas before I spend more.

HEW

It could be the coolant sensor which is under the throttle body and should be tested with a high impedance multimeter as the resistance changes with temperature.

Low water level will also cause overfuelling as there is no water around the sensor.